PIP(2) regulates psychostimulant behaviors through its interaction with a membrane protein

Phosphatidylinositol (4,5)-bisphosphate (PIP(2)) regulates the function of ion channels and transporters. Here, we demonstrate that PIP(2) directly binds the human dopamine (DA) transporter (hDAT), a key regulator of DA homeostasis and a target of the psychostimulant amphetamine (AMPH). This binding occurs through electrostatic interactions with positively charged hDAT N-terminal residues and is shown to facilitate AMPH-induced, DAT-mediated DA efflux and the psychomotor properties of AMPH. Substitution of these residues with uncharged amino acids reduces hDAT-PIP(2) interactions and AMPH-induced DA efflux, without altering the hDAT physiological function of DA uptake. We evaluated, for the first time, the significance of this interaction in vivo using locomotion as a behavioral assay in Drosophila melanogaster. Expression of mutated hDAT with reduced PIP(2) interaction in Drosophila DA neurons impairs AMPH-induced locomotion without altering basal locomotion. We present the first demonstration of how PIP(2) interactions with a membrane protein can regulate the behaviors of complex organisms.